Accidental injuries caused by operation of power driven machinery and equipment can create pinch points. Serious personal injuries have occurred and are foreseeable in the use of lift gates and pedestrian-operated industrial trucks.
Lift gates are provided on various vehicles such as tractor-trailers, delivery vans, moving vans and in a modified form on vehicles for transporting handicapped persons in wheelchairs. Broadly defined, lift gates are movable platforms which may be lowered to load cargo onto the lift gate and then raised to a truck bed or vehicle doorway. As a lift gate is moved to its raised position, it is driven into contact with or moved closely adjacent to the truck bed or vehicle body creating a pinch point. Foreseeable injuries to the foot of a person standing on a lift gate or the hand or arm of a person standing next to a lift gate, perhaps steadying a load on the lift gate, will occur if such body parts are placed in the pinch point between the lift gate and the truck bed or vehicle body. This can result in painful crushing injuries to feet, hands or arms which may cause disfiguring injuries, amputation, or even death.
Foreseeable improper operation of a lift gate can also cause damage to property transported by the lift gate if an object becomes caught between the lift gate and the truck bed or vehicle body. For example, moving vans used by professional movers and untrained individuals frequently are equipped with hydraulically-operated lift gates. If a load is improperly placed on the lift gate, it can become wedged in the pinch point resulting in damage to the property on the lift gate or the lift gate mechanism itself. If a load is improperly loaded and becomes caught in the pinch point, it is foreseeable that the load could shift or even fall off the lift gate, causing injury to people near on or around the lift gate.
One example of a prior art lift gate which incorporates a safety device is disclosed in U.S. Pat. No. 4,540,329 issued to Martin. The safety device disclosed in the Martin patent is intended to allow the lift gate to be safely lowered to the ground and minimize the chance for injury as the lift gate is lowered to the ground. The Martin device does not include any provision for preventing injury as the lift gate is raised. In fact, the structure of the lift gate disclosed in Martin creates a guillotine-like action wherein the lift gate could sever the foot of a person standing on a lift as the lift gate moves to the point at which it passes by the truck bed to come to a raised position wherein the lift gate is at the same height as the truck bed.
Hydraulic lifts used for transporting handicapped persons in wheelchairs such as that disclosed in U.S. Pat. No. 4,392,771 to Smalley have been developed to minimize the chance of injury when lowering the lift to the ground. Nothing is disclosed in the Smalley patent which would prevent injury in the event that a person's foot or wheelchair became trapped between the lift gate and the vehicle body. A wheelchair-confined person could foreseeably suffer further debilitating injury by having their foot trapped between the gate and the vehicle body. In addition, if a part of the wheelchair became caught between the vehicle body and the rising lift gate, the wheelchair could be damaged or, worse yet, flipped from the ramp on to the ground, possibly resulting in a serious injury accident.
Another Common and foreseeable injury involves pedestrian-operated industrial lift trucks which are moved and guided by an operator walking alongside the lift truck and controlling the lift truck with a handle control. U.S. Pat. No. 2,902,015 to Wylie discloses a safety system for preventing injuries when the handle comes into contact with a wall, post or other object trapping or injuring the operator. The Wylie device does not include any safety system to prevent the industrial truck from overrunning the foot or even leg of the lift truck operator. The operator typically walks alongside or in front of the pedestrian-operated industrial truck which moves at walking speed or faster, sometimes within a few inches of an operator's foot. It is therefore foreseeable that an operator's foot or leg could become trapped between the bed of the industrial lift truck and the floor over which the truck is moved. It is foreseeable that a crushing injury to an operator's foot or leg and serious lacerations could occur if they are overrun by the pedestrian-operated industrial lift truck.
The above-stated foreseeable hazards and others establish that there is a long-felt need for a device for preventing injury as a result of the operation of industrial lift trucks or lift gates.